LU-7084 mem: code cleanup for memory allocation

LU-7084 mem: code cleanup for memory allocation

This patch just want fix some memory allocation issues.

Signed-off-by: Yang Sheng <yang.sheng@intel.com>
Change-Id: I53d622d5c4e71ce42488a6cfce17a10063cf4f4d
Reviewed-on: http://review.whamcloud.com/17673
Tested-by: Jenkins
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>